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Feb. 26, 1929. 1,7.03563 Y R. M. wiss K ADIO TUNING DEVICE Filed April 8, 1925 Patented F eb.26, 1 929.

noemt M. WISE, or OAKLAND, cannoni GRAY & DANIELSQN MFG. CO., SAN y, SHIP CNSISTING QF THOMAS B. GRAY AED RADIO TUNING DEVCJ.

Application ed April 8, 1925. semi ne. aisee.

This invent' Y relates to a device 'for tuning radio "irequency circuits, and more i'iarticularly to a device whereby a plurality ot circuits can be tuned simultaneously.

' It is now quite common, in connection with radio signaling,"to use `plurality of circuits that are tuned to a treq'uencyof a very high ord 3i. I For example, in radio reception, there may be two yor more stages ot ra-oio frequency amplification, in which the associated circuits are all to be tuned to a carrier wave. t has been proposed, in the past to provide a common control for all such circuits, whereby a single manipulation only is needed for tuning all ofthe circuits. Such schemes have not met with material success, due to several `factors now to be discussed.

ln the first place, it isa very diicult mattei' to match a plurality ot tuning devices, whether they be variable Vinductances or variable condensers, in such manner that when varied, theyl keep each of the associated lcircuits in substantially eXact tune with all the other circuits. Furthermore, when manipulating devices operating in connection with radio frequency energy, it is Around that the location of these devices relative to other objects has a very material effect upon the tuning; for example, stray capacitance and inductance between elements or" the same or diderent circuits may easily cause these edects. The result is that 'even it exact equality be present in the tuning of a plurality oi' circuits, there is no certainty that the equality will be maintained as the timing devices are moved in the process of timing. j

It is one of the objects of my invention to maire it possible to adjust the tuning devices separately and independently, while in no wise interfering with their simultaneous operation when desired. In this way, it is possible to adjust the tuning ot the circuits roughly by simultaneous tuning, and then to adjust the circuits independently by a iine adjustment.

The present invention is best exeinpliiied in variable condensers, in which there are reiatively movable plates; it-is therefore another object of my invention torniale it possible, in condensers that are inechanicall connected tor simultaneous operation, to

geous features, some ot which, with the toreroi will be set forth at length in the iollou description, where l siiall outline in ruil that torni the invention vrhich I have selected for illustration in the drawings accompanying and forming part of the present specification. Ai liough l have shown in the drawngs but one emb diinent my invention, l do not desire to be limited thereto, since the invention as deined in the claims may be embodied in other forms also. I

leferri ig to the drawings:

Figure 1 is a rear view of a portion of a panel on which a pair ot condensers are mounted, and which embody my invention, some of the parts being broken away; and

Fig. 2 is a top plan view of the condensers and the panel illustrated in Fig. 1.

In the present instance I illustrate the invention as applied to condensers built in accordance with the disclosure in a prior application led July 26, 192e, in my naine entitled Variable condenser and having Seria-l Number 728580. Furthermore, I illustrate a panel mounting 11, which is now quite connnon in radio receiving sets. One of the condenser structures 12 is mounted directly'on this panel, and will now be described.

In the present instance the condenser structure 12 has a supporting disc 13 of insulation material, which is fastened upon the baclr of panel 11 by the aid of a plurality of screws 11i. Projections such asl extend from the disc 13 and serve not only to acconirnocate the screws 1", but also to space the disc and the structure carried thereby Jfrom the panel l1. This structure includes the movable sets of condenser plates 16 and 17, which are arranged to overlap to any desired extent between limits. To support these sets of plates, a pair ot stationary rods or studs 18 and 19 is provided, which studs are rigidly fastened at one end to disc 13, inthe projections 2O on this disc. A series or' brass spacers 21 is passed over each stud, and the plates lo and 1T have ears 22 that are passed over the studs between the spacers. The ears are each soldered to the spacers, Which are so arranged that the plates 16 and 17 interleave.

The spacers 21 and platesl 16 and 17 are mounted for rotation on studs 18 and '19, and for producing this rotation, gears 23 and 24 vare fastened to the end spacers. These gears ,vhichinterinesh, are preferably made from insulation material, and are'journaled n studs 18 and 19. ln order tohold the sets of plates 16 and 17 against axial removal, and 'for providing astiileningmember, a strip 25 ci' insulation is placed between the studs 18 and 19, andbinding poststructures 26 areused to hold the strip `and the plate assemblies together. lt is evident that overlaps the adjacentear of the next plate inthe set, and are joined as by soldering.

The result is that the ears of a series torni practically a solid barsuch as 29, connecting allY ofthe plates of a set. Furthermore, each binding post structure 26. includes aY terminal 30 having ears by the aid .of Which connections can be made to acirciiit, and to which pigtail connectionsisuch as 31 may leadfrom the associated plate-assembly 16 or 17.

Siiihcient friction is provided in the moving parts, asis customary, to ensure that the condenserplates can be retained in. any rela.- tive position until it is desired to 'change the setting.

The operation of gears 23y and24, and confv Y sequent-ly of the plates 16 and 17 is eilected in this instance by the aid of a small pinion 32 meshing with gear 23. This pinion a shaft 3.3 extending through panel 11 as Well as through discV 13. At the tree extremity and on the front side ot the panel 11, the shaftcarries any Well-known form ot tunf ing-@dial 34, having a knob 35 for. manual,k

control. lt is evident. that manipulation of dial34 by the aid of knob 35 causes a corresponding rotation of gears 23and 24. The piniony 32 isheld in. place against removal by .the aid ot a 'forked member 36 of thin metal straddling the shaft 33 on the rear side oie the disc 13. This member is held in place byy a screw 37 engaging the disc 13, as Well as by a projection 38 entering into an aperture 39 in this disc.

ln order to limit the extent of movement of thezplate structures 16 and 17, a pair of stops 40. and 41 is provided on the rear of adapted to cooperate' gear 23, which stops are With a stationary stop 43 located on tlie disc to condenser 44.

With the type ot' condenser disclosed, lioW- y ever,.it becomes a simple matter to provide another similar condenser structure such 44 which can be adjusted by the aid of the same knob 35V simultaneously with the vadjustment of condenser' 12. All that it is necessary to do is to intermesh the adjacent gears 45 and 23 of the condenser structures.

When this is done, itis evident that all of the gearing is rotated by rotation oi pinion 32. Gf course in the condenser' structure 44, there is no equivalent to this pinion.

The arrangement as now described is such that both condensers12 and 44 areA adjusted in unison. In accordance with myl inven-V tion, it is possible to impart a supplementary movement in either direction to the second condenser 44, whereby tlieslight irregularities of the two radio frequency circuits associated vriththe condensers, may be coinpensatedl for. This result, I havefound, can be accomplished by taking intoaccount theV mannerin which motion is imparted to gear 45. It 'We consider for the moment that gear 23 is held stationary, and Vthat a planetary motion be imparted tol that it rolls on the periphery ci gear 23, it is evident that the-gears 45 andl 46 otcon- Vdenser 44 Will rotate about their osvnexes.

This rotation Will oi course produce a relativeY movement of the plates of condenser.V 44. ln this ivay, by proper extent oi planetary motion, any desired supplementary adjustment in either direction, can be imparted ln` order to make this planetary movement possible, the condenser structure'44 is bodily mounted on a fiat insulation support 47, by

gear 45, so Y Which'it can be rotated. This pinion meshes ygear of the previous condenser.

surface of the support by lthe aid of bolts Vusual circumstances, any desired supplementarysettinc can be secured for condenser 44. The support 47 has a pair of projections 55 which serve, in conjunction with pinion 50, to limit the movement of the support. It is also possible to ensure against accidental disturbance of the supplementary setting, by providing sufficient friction in the movable parts.

In the present instance a bank of only two condensers is disclosed. It is possible nevertheless ,toA extend the idea to any number of condensers, by a continued succession of mountings, eachrpivoted on an axis of the Furthermore, if only three condensers are to be thus controlled, it is possible 'to-mount a support such as 47 on an axis coincident with that of the other gear 24 of the condenser l2,

y ywhereby substantially a symmetrical arrangement of the three condenser structures would exist.

The description of the apparatus now complete. There remains only a brief outl line of the manner of use of the device.

First of all, the knob 35 carefully turned until that circuit which is associated with condenser Y12 is in tunegrthen due to the mechanicall construction, the circuit with whichy condenser 44 is associated, is also approximately in tune. lTo brin@ it exactly in tune, knob 52 is carefully adjusted. After this first adjustment, the process can be repeated to tune both circuits still more accurately. V'

I claim:

1. In a device of the class described, a plurality of electrical inst-ruments each havinga rotatable shaft, means for mounting said instruments in side by side relationship with said shafts substantially parallel, a control for said instruments, and means for causing relative displacement between certain of said shafts in a plane substantially normal to said shafts to causev relative angularl movement between the shafts of at least two instruments.

2. In a device of the class described, a plurality of instruments each having movable elements, means including a common operating member for simultaneously moving said elements, and means for shifting the position of at least one of said instruments with respect to another one of the instruments to move one of said elements independently of the others. l

3. In a device of the class described, a plurality of electrical instruments each having a rotatable shaft, a base upon which the instruments are mounted, a gear train for operatively connecting said shafts, a gang control shaft for actuatlng'said gear train to simultaneouslyrotate the shafts of said instruments, and means for independently adjusting one of said instrument shafts coniprising means for shifting the pivotal axis of one of the gears of sait train and simultaneously rotating' the sane relative to the base. i I

4. In combination, a pair of electrical tuning devices, each including a gear and a movable element connected to the gear whereby movement may be imparted to the element, the gears of the tuning devices intermcshing whereby simultaneous variation can be secured, and means for imparting to.

one of said gears a planetary movenient with respect to the other, whereby the tuning device associated with the gear having a planetary movement may Je adjusted independently.

5. In combination, a variable tuning device, including a pair of relatively movable elements and a gear for imparting this relative movement, a second tuning device similar to the first mentioned one, a. pivotall Y mounted support for said second tuning device, the axis of the pivot being coincident with that of the gear on the first tuning device, and said second tuning device having a gear meshing with said firstmentioned gear and serving to impart relative motion of the movable elements of the second tuning device simultaneously with the adjustment of the first tuning device, and means for moving said pivotally mounted support about its axis, whereby a planetary motion is imparted to said second gear.

6. In combination, an electrical instrument having a movable element, and a gear mechanically connected to said movable element, a second electrical instrument also having a movable element and a gear mechanically connected thereto, said two gears intermeshing, and a pivotally mounted support for said second instrument, said support having a pivot with an axis coincident with that of the first gear, whereby pivotal movement of the support causes planetary movement of said second gear.

7. In combination, a plurality of variable tuning devices, each of said devices having a movable structure for varying its electrical characteristic, as well as a gear mechanically connected to the structure whereby they move in unison, all of said gears intermeshing, whereby the movable structures can be simultaneously operated, and means whereby the gears associated with at least some of the devices can be independently rotated to impart a supplementary movement to the associated movable structure.

8. In combination, a pair of variable tuning devices, each including a gear and a movable structure the position of which determines the tuning, said structure being 9. In combination,` a lvariable tuningv de.-

vice, including a movable structure the position of which determines the. tuning, anda gear mechanicallyconnected to said structure, a second tuningv device similar tothe first `mentioned one, a pivotally mounted support-tor said second device, the axis oi' the pivot being coincident with that of the gear on the irst device, and said second device having a gear meshing with said irst-mentioned gear and serving to impart motion to themovable structure of the second device simultaneously with the adjustment ot thefirst device, and means for moving said pivotally mounted support about its axis, whereby a planetary motion is imparted to said second gear.

10. In combination, a tuning device having amovable structure the position of mechanically connected to said structure,

whereby they move inv unison, a second tun- Vlng device also havingV a movable'structurej and a, gearmechanically connected thereto,

vsaid two gears intermeshing,and a pivotally mounten support torsaid second 'tuning device, said vsupport havinga pivot with an axis coincidentwith that of the first gear,VV

whereby vpivotal movement of the support causes planetary movement of' said second gear. Y

11. In a device of the class described, a plurality of electrical instruments each having a rotatable shaft for varying the electrical characteristics of the same, each inl strumentbeing mounted upon a separate base, means for supporting said instruments in side by side relationship with said shafts'v noone: M'. wrsn y 

